1. Field of the Invention
This invention pertains to cranes, and more particularly to a cable stay crane in which multiple loads are moved between spaced positions with minimum applied stress to the crane.
2. Statement of the Prior Art
Gantry cranes have long been in existence wherein a horizontally extending gantry defines a track for a movable load trolley and is supported either at its center or at both ends for permitting a load to be lifted vertically by cable means in a direction towards the trolley and transported between longitudinally spaced positions underlying the gantry. Where such gantry crane is supported at its center, counterweight means on one side of the gantry center support have been previously utilized to compensate for the trolley supported load on the opposite side thereof. Insofar as known, the present invention represents the first such gantry type crane, wherein a working load is transported between two positions on a portion of the gantry to one side of the gantry center support, while a second equal load is transported between two positions by a second trolley on the opposite side of the center support and moved at the same speed to continuously equalize the applied load acting through the gantry on that center support.